To timely understand insulation state of GIS equipment

on-line monitoring of partial discharge is necessary. According to the existing UHF methods and the analysis on a partial discharge case of a 220 k V substation

the authors propose that by changing the operation mode of GIS equipment and using a variety of testing instruments for integrated diagnosis

the uncertain interferences from instrument itself and external environment can be effectively excluded. Hence the accuracy of partial discharge monitoring and positioning results can be improved. The proposed method may facilitae disassembly processing. Operational experience shows that the UHF partial discharge monitoring system installed on GIS equipment can timely detect hidden troubles to ensure safe and stable operation of the equipment.